Head Neurology Flashcards
1
Q
What are the 3 divisions of the Trigeminal Nerve (CN V)?
A
(1) V1 - Ophthalmic Division
(2) V2 - Maxillary Division
(3) V3 - Mandibular Division
2
Q
What are the 5 cutaneous nerves that are derived from the Ophthalmic Nerve (CN V1)?
A
(1) Supra-orbital
(2) Supratrochlear
(3) Lacrimal
(4) Infratrochlear
(5) External Nasal
3
Q
Ophthalmic Nerve (CN V1)
A
- Provides cutaneous innervation from forehead to the tip of the nose
- Sensory only
4
Q
Maxillary Nerve (CN V2)
A
- Provides cutaneous innervation from lateral nose, cheeks and maxillary region
- Sensory only
5
Q
Mandibular Nerve (CN V3)
A
- Provides cutaneous innervation to the Mandible, lateral to the side of the head, anterior to the ear (also sensation to chin)
- Mixed motor and sensory
6
Q
Cutaneous innervation of the posterior head is from what nerve?
A
Posterior Rami of Cervical Spinal Nerves
7
Q
Cutaneous innervation of the lateral head, posterior to the ear, is from what nerve?
A
Anterior Rami of Spinal Nerves
8
Q
Cutaneous Nerve Derivatives of CN V1: Supra-Orbital N
- Origin:
- Course:
- Distribution:
A
- Origin: Largest branch from bifurcation of Frontal N, approximately in the middle of orbital roof
- Course: Continues anteriorly along the roof of the orbit, emerging via supra-orbital notch or foramen; ascends forehead, breaking into branches
- Distribution: Mucosa of Frontal Sinus; skin and conjuctiva of middle superior eyelid; skin and pericranium of anterolateral forehead and scalp to vertex
9
Q
Cutaneous Nerve Derivatives of CN V1: Supratrochlear N
- Origin:
- Course:
- Distribution:
A
- Origin: Smaller branch from bifurcation of Frontal N, approximately in middle of orbital roof
- Course: Continues anteromedially along roof of orbit, passing lateral to trochlea and ascending forehead
- Distribution: Skin and conjuctiva of medial aspect of superior eyelid; skin and pericranium of anteromedial forehead
10
Q
Cutaneous Nerve Derivatives of CN V1: Lacrimal N
- Origin:
- Course:
- Distribution:
A
- Origin: Smallest branch from trifurcation of CN V1, proximal to superior orbital fissure
- Course: Runs superolaterally through orbit, receiving secretomotor fibers via a communicating branch from the Zygomaticotemporal N
- Distribution: Lacrimal Gland (secretomotor fibers); small area of skin and conjuctiva of lateral part of superior eye
11
Q
Cutaneous Nerve Derivatives of CN V1: Infratrochlear N
- Origin:
- Course:
- Distribution:
A
- Origin: Terminal branch (with Anterior Ethmoidal N) of Nasociliary N
- Course: Follows medial wall of orbit, passing inferior to the trochlea
- Distribution: Skin lateral to roof of nose; skin and conjuctiva of eyelids adjacent to medial canthus, lacrimal sac and lacrimal caruncle
12
Q
Cutaneous Nerve Derivatives of CN V1: External Nasal N
- Origin:
- Course:
- Distribution:
A
- Origin: Terminal branch of Anterior Ethmoidal N (of Nasociliary N)
- Course: Emerges from nasal cavity by passing between nasal bone and lateral nasal cartilage
- Distribution: Skin of nasal ala, vestibule, and dorsum of nose including apex
13
Q
What are the 3 cutaneous nerves that are derived from the Maxillary Nerve (CN V2)?
A
(1) Infra-orbital
(2) Zygomaticofacial
(3) Zygomaticotemporal
14
Q
Cutaneous Nerve Derivatives of CN V2: Infra-Orbital N
- Origin:
- Course:
- Distribution:
A
- Origin: Continuation of CN V2 distal to its entrance into the orbit via the inferior orbital fissure
- Course: Traverses infra-orbital groove and canal in orbital floor, giving rise to superior alveolar branches; emerges via infra-orbital foramen and divides into inferior palpebral, internal and external nasal, and superior labial branches
- Distribution: Mucosa of maxillary sinus; premolar, canine, and incisor maxillary teeth; skin and conjuctiva of inferior eyelid; skin of cheek, lateral nose and anteroinferior nasal septum; skin and oral mucosa of superior lip
15
Q
Cutaneous Nerve Derivatives of CN V2: Zygomaticofacial N
- Origin:
- Course:
- Distribution:
A
- Origin: Smaller terminal branch (with zygomaticotemporal n) of Zygomatic N
- Course: Traverses zygomaticofacial canal in zygomatic bone at inferolateral angle of orbit
- Distribution: Skin on prominence of cheek
16
Q
Cutaneous Nerve Derivatives of CN V2: Zygomaticotemporal N
- Origin:
- Course:
- Distribution:
A
- Origin: Larger terminal branch (with zygomaticofacial n) of Zygomatic N
- Course: Sends communicating branch to Lacrimal N in orbit; then passes to temporal fossa via zygomaticotemporal canal in zygomatic bone
- Distribution: Hairless skin anterior part of temporal fossa
17
Q
What are the 3 cutaneous nerves that are derived from the Mandibular Nerve (CN V3)?
A
(1) Auriculotemporal
(2) Buccal
(3) Mental
18
Q
Cutaneous Nerve Derivatives of CN V3: Auriculotemporal N
- Origin:
- Course:
- Distribution:
A
- Origin: In infratemporal fossa via two roots from posterior trunk of CN V3 that encircle middle meningeal A
- Course: Passes posteriorly deep to ramus of mandible and superior deep part of parotid gland, emerging posterior to TMJ
- Distribution: Skin anterior to auricle and posterior 2/3rds of temporal region; skin of tragus and adjacent helix of auricle; skin of roof of external acoustic meatus; skin of superior tympanic membrane
19
Q
Cutaneous Nerve Derivatives of CN V3: Buccal N
- Origin:
- Course:
- Distribution:
A
- Origin: In infratemporal fossa as sensory branch of anterior trunk of CN V3
- Course: Passes between two parts of lateral pterygoid muscle, emerging anteriorly from cover of ramus of mandible and masseter, uniting with buccal branches of Facial N
- Distribution: Skin and oral mucosa of cheek; buccal gingivae (gums) adjacent to second and third molars
20
Q
Cutaneous Nerve Derivatives of CN V3: Mental N
- Origin:
- Course:
- Distribution:
A
- Origin: Terminal branch of Inferior Alveolar N (CN V3)
- Course: Emerges from mandibular canal via mental foramen in anterolateral aspect of body of mandible
- Distribution: Skin of chin; oral mucosa of inferior lip
21
Q
Ophthalmic Nerve (CN V1)
A
- Superior division of the Trigeminal N
- Smallest of the three divisions of CN V
- Sensory
- Enters the orbit through the Superior Orbital Fissure -> trifurcates into the frontal, nasociliary, and lacrimal nerves
- Except for the external nasal nerve, the cutaneous branches of CN V1 reach the skin of the face via the orbital opening
22
Q
Branches of Ophthalmic N: Frontal N
A
- Located between the Lacrimal and Nasociliary nerves
- Largest branch of V1
- Runs along the roof of the orbit toward the orbital opening, bifurcating midway into the cutaneous supra-orbital and supratrochlear nerves, distributed to the forehead and scalp
23
Q
Branches of Ophthalmic N: Lacrimal N
A
- Most lateral of the nerves that branch off the Ophthalmic N
- Smallest branch of V1
- Primarily a cutaneous branch but also conveys some secretomotor fibers via a communicating branch from a ganglion associated with the maxillary n for innervation of the lacrimal gland
24
Q
Branches of Ophthalmic N: Nasociliary N
A
- Most medial of the nerves that branch off the Ophthalmic N
- Intermediate branch of V1
- Supplies branches to the eyeball and divides within the orbit into the Posterior Ethmoidal, Anterior Ethmoidal, and Infratrochlear nerves that supply the cutaneous innervation of the external nose
25
Maxillary Nerve (CN V3)
- Intermediate division of the Trigeminal Nerve
- Sensory
- Leaves the cranium through the Foramen Rotundum
- Enters the Pterygopalatine Fossa where it gives off branches to the Pterygopalatine Ganglion and continues anteriorly, entering the orbit through the Inferior Orbital Fissure
- Gives off the Zygomatic N and passes anteriorly into the Infra-orbital Groove and Foramen as it gives rise to the Infra-orbital nerves
26
What are the two terminal branches of the Zygomatic Nerve?
(1) Zygomaticofacial
(2) Zygomaticotemporal
27
What nerve sends a communicating branch to convey secretomotor fibers to the Lacrimal N?
Zygomatic Nerve
28
Where does the Maxillary N enter the orbit?
Through the Inferior Orbital Fissure
29
Infra-orbital nerve gives off ___ branches, branches to the mucosa of the ___ sinus, and branches to the ___ and __ upper teeth.
- Palatine
- Maxillary
- Middle
- Anterior
30
Mandibular Nerve (CN V3)
- Inferior and largest division of the Trigeminal N
- Passes through the Foramen Ovale
- Has 3 sensory brancehs taht supply the area of skin of the mandible
- Supplies the motor fibers to the muscles of mastication
- Only division of CN V that carries motor fibers
31
What are the 3 sensory branches of the Mandibular Nerve?
- Auriculotemporal
- Buccal
- Mental
32
En route to the skin, the Auriculotemporal N passes deep to the __ ___, conveying secretomotor fibers to it from the ___ ___
- Parotid Gland
- Otic Ganglion
33
Great Auricular Nerve
- Anterior rami C2-3
- Ascends vertically across the SCM, posterior to the External Jugular Vein
- Innervates skin overlying the angle of mandible and inferior lobe of auricle; parotid sheath
34
Lesser Occipital Nerve
- Anterior Ramus C2
- Follows posterior border of SCM, ascends posterior to auricle
- Innervates scalp posterior to the auricle
35
Greater Occipital Nerve
- Posterior Ramus C2
- Pierces trapezius
- Innervates scalp occipital region
36
CN VII emerges from the cranium via:
Stylomastoid Foramen
37
What are the 6 branches of the Facial Nerve (CN VII)?
(1) Posterior Auricle
(2) Cervical
(3) Marginal Mandibular
(4) Buccal
(5) Zygomatic
(6) Temporal
38
Facial Nerve has __, __, and ___ components
Motor, Sensory, Parasympathetic
39
Does the Facial Nerve have cutaneous innervation?
Nope
40
What does the motor component of the Facial N supply?
- Muscles of facial expression
- Superficial muscles of the neck (Platysma)
- Auricular muscles
- Scalp muscles
41
Parasympathetic (Visceral Motor) to Lacrimal Gland
(1) Greater Petrosal N arises from CN VII
(2) Greater Petrosal N joints the Depp Petrosal N (sympathetic) at the Foramen Lacerum to form the N to the Pterygoid Canal
(3) N of Pterygoid Canal travels thru Pterygoid Canal and enters Pterygopalatine Fossa
(4) Parasympathetic fibers from N of Pterygopalatine Canal synapse in Pterygopalatine Ganglin in Pterygopalatine Fossa
(5) Postsynaptic parasympathetic fibers from this ganglion innervate the Lacrimal Gland via the Zygomatic branch of CN V2 and the Lacrimal N (branch of V1)
42
Parasympathetic (Visceral Motor) to Submandibular and Sublingual Gladns
(1) Chorda Tympani branch arises from CN VII
(2) Chorda Tympani passes through the Petrotympanic Fissure between the petrous parts of the temporal bone to join the Lingual N (CN V3) in the infratemporal fossa
(3) Parasympathetic fibers of the Chorda Tympani synapse in the Submandibular Ganglion; postsynaptic fibers follow arteries to glands
